1. Field of the Invention
The present invention relates to a chair with a tiltable backrest that is biased elastically into a resting position and can be tilted under the action of a backwards thrust applied by the back of the user.
More precisely, the invention relates to a chair in which the backrest is connected to a base structure by means of a pair of elastic devices, each of which comprises a top support, inserted in a tubular portion of the backrest, a bottom support, inserted in a tubular element of the base structure, and a flexurally deformable elastic element that enables tilting between the top support and the bottom support.
2. Description of the Related Art
WO 91/03191 discloses a chair with tiltable backrest including a base structure including two rear tubular elements, a backrest and two elastic devices, each of which has a top support inserted in a tubular portion of the backrest, a bottom support inserted in the corresponding tubular element of the base structure, and an elastic element having a top stretch fixed to the top support and a bottom stretch fixed to the bottom support, the elastic element being flexurally deformable to enable tilting between the top support and the bottom support.
In the solution described in WO 91/03191, provided between the facing ends of the two supports of each elastic element is an empty space of ample dimensions for enabling a movement of backwards tilting of the backrest with the desired amplitude. The space of large dimensions between the mobile supports, as described in WO 91/03191, exposes the user to a risk of getting pinched. In order to limit this risk, in the solution described in WO 91/03191 there is provided a bellows-shaped element with flexible structure, which surrounds the open area between the two supports of each elastic element. However, the bellows-shaped element does not completely eliminate the risk of pinching, is subject to failure, and has a negative impact from the aesthetic standpoint.